The invention relates to a method of coding a document for presentation on a presentation apparatus, comprising a step of defining a structure section which specifies a structure of said document in terms of document elements.
The invention also relates to a method of presenting a coded document, which is coded in accordance with the above method of coding a document.
The invention also relates to an apparatus for presenting a coded document, which is coded in accordance with the above method of coding a document.
The invention also relates to an information carrier with a coded document, which is coded in accordance with the above method of coding a document.
The invention also relates to an apparatus for coding a document in accordance with the above method of coding a document.
It is known to code a document, for example a text document or a graphics description (vector graphics, 3D graphics world, etc.), into a description according to a given format. The coded document may be transferred via a network or stored on a storage medium for subsequent presentation by a suitable apparatus. An example of such a format is HTML (Hypertext markup language), which combines the concepts of text markup, hyperlinking and URLs (Uniform Resource Locator). Text markup derives from SGML (Standard Generalized Markup Language) and XML (Extensible Markup Language). HTML is in fact a SGML application. XML has been specified by the W3C (World Wide Web Consortium) and can be considered as a simplified version of SGML. Both SGML and XML provide a way to specify structure in documents. ‘Structure’ refers to the organization of the document and, in case of text, includes matters like paragraph, line break, chapter, etc. The ‘style’ of presentation is coded separately from the document structure, for example in so-called style-sheets. Style refers to matters like font, page size, colors, line spacing, etc. By separating structure and style, a text document together with its markup can be stored once, and from this basic document various versions can be derived while using different style sheets, for example for paperback, hard-cover, or screen display. Each style sheet contains a number of style rules, each of which assigns style properties to a document element selected from the text document. A document element can be selected from the document by means of, for example, the Cascading Style Sheets (CSS) format as described hereinafter. The HTML standard is described in HTML 4.0 Specification, W3C Recommendation, on the Internet at the W3 organization website at “w3.org/TR/REC-html40”, April 1998. The CSS standard is described in the CSS Level 2 Specification W3C Recommendation, at “w3.org/TR/REC-CSS2”, May 1998.
Recently, a set of extensions has been proposed to add additional timing, interaction and media delivery capabilities to HTML. These extensions assign timing properties to the document elements, specifying, for example, for how long a particular element should be presented. Using the timing extensions, any HTML element can be set to appear at a given time, to last for a specified duration, and to repeat (i.e. loop). With the advent of such extensions, it is possible for HTML to be a much more powerful medium for coding documents. Designers can now begin to think of documents not just as a static piece of information, but as a dynamic, interactive presentation. Aside from HTML, other XML-applications are foreseen which also demand extension with timing information.
A disadvantage of such timing extensions is that the timing information is intermingled with the document's structure information, this is undesirable if the document has to be presented on various types of equipment with various levels of sophistication, capacity and processing power, and the presentation schedule has to be optimized with respect to these parameters. Moreover, solving this for the HTML case does not offer a general solution for extending other XML-application formats with similar timing constructs as well; this is laborious and confusing.